一个网站的两个用户之间的对话类型收件箱消息

Question

我想实现两个用户之间的对话类型收件箱消息，其中对话将在两个用户之间分组并显示在收件箱页面上，当单击对话时，将显示两个用户之间的整体聊天记录... . 我有一个数据库架构，但未能对两个用户之间的对话进行分组。我需要一个查询来实现这一点谢谢 这是我的桌子。

1.用户：

• 身份证
• 用户名
• 密码

2.对话：

• conversation_id
• from_user
• to_user

3.消息：

• message_id
• conversation_id
• user_id
• message_text
• message_date
• 看到

因此，如果有人知道如何实现此查询，那么请帮助我，也将不胜感激更改我的架构，谢谢

Answer 1

SELECT conversation FROM
        conversations

WHERE (conversations.from_user = <user parameter>
OR conversations.to_user = <user parameter>) 
AND conversations.from_user <> conversations.to_user

Answer 2

您可以使用如下所示的查询通过对话获取当前用户与最后一条消息的所有对话：

SELECT users.id,
       users.name,
       messages.conversation_id,
       messages.message_id,
       messages.message_text,
       messages.message_date,
       messages.seen
FROM
  (SELECT conversations.conversation_id,
          IF(conversations.from_user = <current_user_id>, conversations.to_user, conversations.from_user) AS interlocutor_id,
          max(messages.message_id) AS last_message_id
   FROM conversations
   LEFT JOIN messages ON conversations.conversation_id = messages.conversation_id
   WHERE convesations.from_id = <current_user_id>
     OR conversations.to_id = <current_user_id>
   GROUP BY conversations.conversation_id) AS t
LEFT JOIN users ON users.id = t.intercolutor_id
LEFT JOIN messages ON messages.message_id = t.last_message_id

如果您需要获取当前用户的所有对话与最后一个 indox 消息，使用：

SELECT users.id,
       users.name,
       messages.conversation_id,
       messages.message_id,
       messages.message_text,
       messages.message_date,
       messages.seen
FROM
  (SELECT conversations.conversation_id,
          IF(conversations.from_user = <current_user_id>, conversations.to_user, conversations.from_user) AS interlocutor_id,
          max(messages.message_id) AS last_message_id
   FROM conversations
   LEFT JOIN messages ON conversations.conversation_id = messages.conversation_id
   WHERE (convesations.from_id = <current_user_id>
          OR conversations.to_id = <current_user_id>)
     AND messages.user_id <> <current_user_id>
   GROUP BY conversations.conversation_id) AS t
LEFT JOIN users ON users.id = t.intercolutor_id
LEFT JOIN messages ON messages.message_id = t.last_message_id

但我认为如果你重写你的数据库方案并且你将在“对话”表中添加最后一条消息的 id，那会比更好的方法。这将使查询更优化

更新：

如果您需要获取与当前用户对话的所有用户的列表：

SELECT t.conversation_id,
       users.id,
       users.name
FROM
  (SELECT conversation_id,
          IF(from_user = <current_user_id>, to_user, from_user) AS interlocutor_id          
   FROM conversations   
   WHERE from_id = <current_user_id>
     OR to_id = <current_user_id>) AS t
LEFT JOIN users ON users.id = t.intercolutor_id

附：您必须将<current_user_id> 替换为当前用户的实际标识符